More than 70% of hydraulic system failures are caused by hydraulic media (mainly hydraulic oil). In addition to the contamination of the medium, the high temperature of the hydraulic oil is also one of the important reasons that affect the normal operation of the hydraulic system, especially in the case of high temperatures in summer. The hydraulic system has a normal operating temperature of 30-50 ° C, a maximum of 70 ° C, and a minimum of 15 ° C. What is the effect of excessive oil temperature on the performance of the hydraulic system, and what are the causes of excessive oil temperature? How to prevent it?